Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Norwalk, United States, as it provides essential information on the sun's ultraviolet radiation intensity. With typical UV levels peaking at a hazardous 10 in the midday hours, awareness of these levels can significantly aid in sunburn prevention and promote long-term skin health. Given Norwalk's Dfa climate, characterized by warm summers, it’s especially important to stay informed about UV exposure risks during peak hours, from late morning to early afternoon, to safeguard your skin and enjoy the sunny days safely.
The UV Index reveals a dynamic ascent and descent throughout the day, peaking with intensity during midday. Starting at a gentle 1 at 7:00 AM, it climbs steadily, reaching 10 by 1:00 PM and maintaining this highest level until 2:00 PM. This critical window indicates significant sun exposure, and it’s essential to take precautions. As the afternoon progresses, the index begins to taper off, dropping to 8 at 3:00 PM, then gradually falling to 1 by 7:00 PM. This data highlights the importance of being sun-smart during the peak hours to minimize UV exposure risks.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels fluctuate significantly, impacting sun exposure and potential skin damage. The high-risk months, identified by an increased UV Index, are April through August, where levels reach a concerning 8 to 11, categorized as either very high to extreme. Notably, June exhibits the peak UV Index of 11, necessitating vigilant sun protection. Residents and visitors are advised to minimize sun exposure during these months, seeking shade and applying broad-spectrum sunscreen regularly, especially during peak hours. In contrast, winter months like January, November, and December present a moderate risk with an UV Index of 3 to 4, allowing for more lenient outdoor activities while still practicing sun safety.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Norwalk | 3 | 5 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |